In addition to Nepenthe's points, one of the main uses of plague/etc. is being able to wear down a foe enough to keep them helpless for a period of time that you can use to hunt them down and kill them. I don't see why we'd want to weaken that method of landing a kill, other than the all-too-common 'make everything easy and the game will be fun' misconception. You're vulnerable, but more or less any non-Rager-without-powers can deal with it, especially for characters who are willing to ask someone else for help. Refresh and related abilities are common and inexpensive for exactly this reason, and the situation you're describing is one of the best reasons to think ahead and have a bunch handy.

valguarnera@carrionfields.com